I'm getting ready to do my inlet manifold gaskets and since I've got the top of the engine off is it worth replacing the injectors? My car (and I guess injectors) has done 143k miles. I can get 12 new injectors for around $100. Am I wasting my cash?

I would be cautious. 12 injectors for $100, that is about $8.33 per injector. They are "normally" $55 - $70. Are you sure they are "new"? are they the "correct" injector? I went and had mine cleaned ultrasonically and then flow and pressure tested. Cost for that was $11 per injector. That way I knew for sure that I was getting the correct injector. Buying "used" injectors is a crap-shoot, you most likely will wind up having them cleaned and tested (I would - especially since replacing them takes a bit of time).

This is a very good site to check if you have the right injectors for your car (http://www.fiveomotorsport.com/Injector_SetsBMW.asp) and TxGR8White is right that you should be careful with 12 injectors for 100 bucks because this is the best site I could find and the cheapest are 38 dollars each for a set of 12.

Thanks guys. Having looked again the injectors are used, but I have bought off this guy before and his used stuff looks brand new. I don't know where he gets his bits from but the parts are great. They are original BMW injectors. I bought the intake manifold gaskets from him and they are spotless, no cracks or any other issues (€35 including shipping for complete set) http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=320222366558&ssPageName=STRK:MEWA:IT&ih=011.

What do you think?

clean yours!!!!

Thanks guys. Having looked again the injectors are used, but I have bought off this guy before and his used stuff looks brand new. I don't know where he gets his bits from but the parts are great. They are original BMW injectors. I bought the intake manifold gaskets from him and they are spotless, no cracks or any other issues (€35 including shipping for complete set) http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=320222366558&ssPageName=STRK:MEWA:IT&ih=011 (http://rover.ebay.com/rover/1/711-1751-2978-71/1?AID=5463217&PID=2518995&loc=http%3A%2F%2Fcgi.ebay.co.uk%2Fws%2FeBayISAPI.d ll%3FViewItem%26rd%3D1%26item%3D320222366558%26ssP ageName%3DSTRK%3AMEWA%3AIT%26ih%3D011).

What do you think?

Having gone down this road before (twice), I strongly urge you to think about what you put back in if you are indeed going to do the intake gaskets. I re-used my low-mileage IM gaskets on the advice of "senior" 8 owners archived posts on another forum, and it was a disaster. I got to do the IM gasket thing twice, once with my clean, spotless, no apparent cracks IM gaskets, and then 2 weeks later when the car still wouldn't run properly, with new gaskets.

Do yourself a favor and make certain what you put back is in very good codition (this includes having the injectors cleaned and tested), or you run the risk of doing this job again in the very immediate future.

This is not the place where you really want to go the "cheap" route.

that reminds me of a flowchart

Having gone down this road before (twice), I strongly urge you to think about what you put back in if you are indeed going to do the intake gaskets. I re-use my low-mileage IM gaskets on the advice of "senior" 8 owners archived posts on another forum, and it was a disaster.

Steffen, hate to call you on this but I don't think anyone on "another forum" strongly recommended you re-use the old IMs, It appears that you made the decision and used the advice of a "Super V12 Guru" that you met in your state, not on the forum!

Copy of your post:

"
Subject:
...Gaskets were new, just not brand new... (73 views)
Message: ...and for $600, it didn't seem worth the price tag. I would have had they been all messed up and brittle, but that wasn't the case.
Super V12 Guru also said that most times you re-use what you got unless you had catastrophic engine overheat and failure - which wasn't the case..."

I have re-used IM only when the owner was not in a financial position to afford new ones, they did work BUT I would not guarantee these or my work up front with them. The rubber does get hard quite quickly on the IMs and will take a set, any movement, pressure on the manifolds, or improperly sealed when put back on will result in a leaker!

You can't cheep-out with these.

Ed,
First of all I did NOT say it was "strongly recommended" I said "on the advice of 'senior' 8 owners"
I appreciate you "calling me " on it, but please look at this post:
http://bimmer.roadfly.com/bmw/forums/e31/8172008-1.html (http://bimmer.roadfly.com/bmw/forums/e31/8172008-1.html)
It references the following posts by :
PumpedTsi : http://bimmer.roadfly.com/bmw/forums/e31/5754530-1.html,
Wuffer: http://bimmer.roadfly.com/bmw/forums/e31/5763003-1.html and http://bimmer.roadfly.com/bmw/forums/e31/5760189-1.html

If you look at these threads in the order they are listed here, you will see what I am talking about. To clear up any miscommunications, I (unlike most people) searched the archives there and came up with the info from these guys. Guys that have been members there for quite some time - I assumed they were speaking from experience - I am sure they do, It is from this information, that I proceeded with my IM gasket repair. As I have stated previously, I am NOT dissing the fantastic blue stuff - I was merely posting my personal observations while using this, and while attempting to re-use the gaskets themselves as it was indicated in the above mentioned posts. The heat that I received from the "Hylomar Incident" was in my opinion uncalled for from the "seasoned 8 owners" that provided me with this info to begin with. As I have also stated in earlier posts, I should have gone with my own instincts on this repair, as I will in the future. I responded to the thread here to give the original poster the opportunity to hear various "other" scenarios that have occured. I hold no grudges against you or any of the above mentioned people, but please take the time to read the linked posts and if you still feel I am wrong with what I have read, let me know.

:)

that reminds me of a flowchart


This is great and going to my work.

I am no expert, but I would never reuse a gasket unless I was stuck ie. no money or in the middle of the desert. JMO.

Yo,
Rod

The IM gasket on the 850 is not really a gasket like most of us imagine when we hear the word "gasket". It is actually called a "gasket-flange" by BMW and is in reality a vibration isolator for the aluminum intake runners that are cantilevered off of these "gaskets". They are quite "heavy-duty" looking, and I believe that is why the question of being able to re-use them keeps coming up.

Tx,

K bro... got you on that.

Yo,
Rod

i was trying to hit on the humor side a little.
i would not mess with the injectors unless i would have to.

preventative maintenance while you are already there....

my advice was only IF he was in a bind money wise.....I have done this before and all was good but I am EXTREMELY thorough with my maint and if not enough attention is given you "could" end up with a slight leak............obviously change them if you can afford it or if they are original and really deteriorated.........just my .02

That's how it was understood by me..

I really hope for the day, with a case or two of beer (maybe some tequila!),
that the whole "Hylomar Spat" will be a laugh amongst all. This is crazy. Not that big of a deal? A misunderstanding, misintrepretation, diff of opinion, whatever- why does this subject continue to bring the worst out of everyone? Personally, we are not this way? Arguing diff of perspective of history is "backin' up", drop it and move on! We are better folks than this.

Ed, I can respect your passion for this particular subject but I would prefer if you could take this "attitude" offline or RF Sir.... And yes if you have something to say to me, again, OFFLINE


Steffen, hate to call you on this but I don't think anyone on "another forum" strongly recommended you re-use the old IMs, It appears that you made the decision and used the advice of a "Super V12 Guru" that you met in your state, not on the forum!

Copy of your post:

"
Subject:
...Gaskets were new, just not brand new... (73 views)
Message: ...and for $600, it didn't seem worth the price tag. I would have had they been all messed up and brittle, but that wasn't the case.
Super V12 Guru also said that most times you re-use what you got unless you had catastrophic engine overheat and failure - which wasn't the case..."

I have re-used IM only when the owner was not in a financial position to afford new ones, they did work BUT I would not guarantee these or my work up front with them. The rubber does get hard quite quickly on the IMs and will take a set, any movement, pressure on the manifolds, or improperly sealed when put back on will result in a leaker!

You can't cheep-out with these.

Ionel (EthanW)- May I remind you that this thread is about injectors and IM replacements, your post is O/T

Probably would be good to follow your own advice first before ordering what others should or should not do!

What have i done... :(.

Thanks for all your opinions guys. I think I'm going to leave my injectors as they are as I have no evidence that's there's anything wrong with them. The point of the question was really to ascertain if injectors are a consumable item and whether after high miles they should be replaced and I'm getting a resounding NO to that. You've worried me about the IM gaskets, I've just had another look at my "new" ones at they are in great shape but are clearly used and the "hardening" thing worries me. I can afford new ones but am always looking to save money as there is so much left to do on the car. I've got rust and minor crash damage to contend with this summer so I need to put some serious cash aside for that. I've got a contact in Bosch Germany procurement :cool, so I may be able to get a deal on new gaskets. Thanks again.

my advice was only IF he was in a bind money wise.....I have done this before and all was good but I am EXTREMELY thorough with my maint and if not enough attention is given you "could" end up with a slight leak............obviously change them if you can afford it or if they are original and really deteriorated.........just my .02

That's how it was understood by me..

The Intake Manifold gaskets on the early V12 are really expensive, $96 dollars each needing 4, and most of the time they never go bad but it can lead to multiple problems when they do. I changed mine because they were cracked all over, hot spotted, and just general pieces of crap.

Also it is not fun at all to even get to these things because it is a very tight fit in between the manifold and the valve cover for those bottom intake nuts. When I took my very top of the motor apart I learned why people never change stuff on these cars and let them just die slowly.:(

What have i done... :(.

You asked good questions and are getting a lot of good response. Particularly about IM gaskets. There is a huge amount of controversy about what should be done or not done and you should be getting the idea that unless you know what you are doing, it is far better to replace the IM gaskets with new. There are many reasons for "older" M gaskets to fail when reused so it is better to error on the safe side, it is NOT a fun job for sure and to do it twice isn't a good thing.

As another pointer, when you look at your IM gaskets you should see a raised ridge around both sides of the gasket, on new IM gaskets this ridge is rather pronounced and rounded and when mounted over time this will flatten, hence when reusing, the sealing properties are compromised and sealants will not always help.

One other point worth mentioning, on the outward side of each manifold, there are two "lord" mounts that help take the strain of the overhung load that the manifold presents on the IM gaskets. These should always be replaced, if not, the IM gaskets will have to support the entire overhung load and will try to pull away from the heads resulting in a leak.

Further, NEVER push down on the intake manifolds EVER. It is possible to deform the IM gaskets aluminum backing plate, even new ones may not recover and will not seal. Take care when installing the manifolds that you don't inadvertently push down on them either.

HTH